Identification of isoenzymes using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Authors

  • Julie Hardouin,

    1. Laboratoire de Spectrométrie de Masse Bio-Organique, CNRS—UMR 6014, UFR des Sciences, Université de Rouen, 76 821 Mont-Saint-Aignan Cedex, France
    2. Centre de Biophysique Moléculaire, C.N.R.S., Rue Charles Sadron, 45 075 Orléans Cedex 02, France
    Search for more papers by this author
  • Marie Hubert-Roux,

    1. Laboratoire de Spectrométrie de Masse Bio-Organique, CNRS—UMR 6014, UFR des Sciences, Université de Rouen, 76 821 Mont-Saint-Aignan Cedex, France
    Search for more papers by this author
  • Agnès F. Delmas,

    1. Centre de Biophysique Moléculaire, C.N.R.S., Rue Charles Sadron, 45 075 Orléans Cedex 02, France
    Search for more papers by this author
  • Catherine Lange

    Corresponding author
    1. Laboratoire de Spectrométrie de Masse Bio-Organique, CNRS—UMR 6014, UFR des Sciences, Université de Rouen, 76 821 Mont-Saint-Aignan Cedex, France
    • Laboratoire de Spectrométrie de Masse Bio-Organique, Université de Rouen, Rue Tesnière, 76 821 Mont-Saint-Aignan Cedex, France.
    Search for more papers by this author

Abstract

The identification of isoforms is one of the great challenges in proteomics due to the large number of identical amino acids preventing their separations by two-dimensional electrophoresis. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) has become a rapid and sensitive tool in proteomics, notably with the new instrumental improvements. In this study, we used several acquisition modes of MALDI-TOFMS to identify isoforms of porcine glutathiones S-transferase. The use of multiple proteases coupled to the different acquisition modes of MALDI-TOFMS (linear, reflectron, post-source decay (PSD) and in-source decay, positive and negative modes) allowed the identification of two sequences. Moreover, a third sequence is pointed out from a PSD study of a tryptic ion revealing the modification of the amino acid tyrosine 146 to phenylalanine. Copyright © 2006 John Wiley & Sons, Ltd.

Ancillary